Theres a brief post here or on candlepowerforums about changing the LED. Seems you undo the bolts and it just pulls apart(quite tight though). I assume the LED is soldered. The MinewtX2 has a T bin SSC so upgrading to U2 bin will be a nice boost. The X2 is a nice light as is(but a little more light is always good).

dkindy I got the advertised runtimes on my x2. I was really happy with it.

edit... disassembly here.